Furniture spring



May 21, 1935. 1.. KIMBRIG FURNITURE SPRING Filed April 30, 1954 MM n T N m VK T N T w? oY Patented May 1935 :.?*,"U NITED:ESTATES P TE T" I "UFURNITURE'S'PRING Louis Kimbrig, Brooklyn, r1. Y. "Application April 30, 1934, S81'ial Nb.- 723,122

My invention relates to spiral springs of .the

cylindrical and helical type, and particularly to such. springs with closed outermost or end convolutions. J i

Spiral springs are designed for utilization generally by compression or extension alonga line parallelto their axes, and arevery largely employed inarticles of furniture such as bed springs, mattresses, cushion and spring seats and the like though use thereof is made in-many other fields. Springs of this type, while same may, are very seldom used singly, but several thereof are generally tied, linked or otherwise secured together intoa complete assembly. The springs are tied and linked together at their extremities,'- i. e., the outermost'or end 'convoluti'ons, and when secured in place in and as a part of an article of furniture, same are likewise secured or attached by their extremities, i e.,- their outermost or end convolutions. These, therefore, havesome measure of support and reinforcement.

It is of paramount importance, however, that the inner coils of thesespring'swhich do not have this supportretain their predetermined size and shape, in order that theymay function perfectly to absorb and dissipate the stresses and strains imparted thereto.- v i In such connection, it is essential that the outermost or endconvolutions which directly receive the impacts of the applied forces be of such character as to absorbat least aportion of such forces. most or end convolution is directly transmitted and communicated to the inner coils, to the destruction of the latters -eflicient operation, and

to have a spring'of any'useful life, provision must be made to insure the stability of the end conv'olutions so far as their size and shapeis concerned without affecting its resilient character. It is an object, therefore, ofmy invention to provide aspring of the character described with "an outermost or'end. convolution which will not vslip,lc osen, or otherwise change its size and'shape during usage. I, j In connection with the uses to which springs of this type are often put, forces are sometimes applied thereto not along a line parallel to their axesand it is important that these angular forces be,;partly abs orbed and dissipated before same are "passed along to the inner coils of the spring, in order that they do not act upon and distort said inner coils.

It is a further object, therefore, of my invention to provide a spring of the character de- Any twistingor distortion of the outer-- 2 Claims. (or. 5 -256) scribedwith an outermost or end convolution which will absorb at least part of the forces applied thereto along a plane or line not parallel to the axis of the spring.

Further objects. of myinvention will be obvious from the following description of one embodiment thereof, and in part be pointed out hereinbelow.

.In the drawing annexed hereto and made a part hereof:

. Figure 1 is a perspective ofone form of device constructed according to and embodying my said invention; the outermost or end "convolutions being open, in position to be locked and closed;

and

Fig-2 is aview similar to" Fig. l of a portion of a similar form of, device but with the outermost or end convolution closed and locked. In this figure, I also illustrate the manner in which Ilink-together several spring units to form' a complete spring assembly. v .In the drawing, reference numeral designates the spring generally, comprising body portion' l2 and end. portion 14 integral therewith. Body [2 is formed into a number of substantially circular spiral coils I 6, and end I4 is formed into the outermost or end convolution [8. I have illustrated my invention as applied toa spiral spring of the cylindrical type, but same is not limited thereto, and may be applied to springs of the-helical or other types. 1 End [4 is integral withand an extension from body [2 .of spring III, which, as a unit, is formed of a single length of wire.

,In' accordance with my invention, the outermost or end convolution (which outermost or end convolution I shall hereinafter refer to as a loop) is formed into a completely closed plane geometric figure. In the drawing, I have illustrated my invention as applied to an outermost or end loop [8 of substantially square shape, since'this is my preferred embodiment. My invention, however, is also applicable to a triangular outermost or end loop, and to a five sided or pentagonal outermost or end loop, etc.

In discussing the shape of the outermost or end loop I use the word substantially because while the sides of the figure are shown to be straight, same need not be, but may be curved slightly; andfurther because the junctionscr meeting points of the component straight sides 20 of loop l8 are bowed outwardly from said sides 20 to form open loops or U-bends 22 at the corners of the figure, which open loops or U-bends (as they will interchangeably be referred to) are composed of trough or stirrup portions 24 and side wall portions 26. .Each of these loops or U-bends is identical in size and shape with every other loop or bend. Troughs 2 are equal in length to side walls 26, and while these are shown to be about half as long as the sides 2E3 of the loop i8, same may beat the minimum-a fourth or even an eighth as large as said sides, andi'at the maximumequal thereto in length.

If it is desired, as shown, to provide an outermost or end loop of square shape, at least five open loops or U-bends must be provided in the end portion of the spring, since, in accordance with my invention, to close the loop, the last or endmost of the U-bends is superposed upon the first U-bend, i. e., the U-bend most adjacent the body portion of the spring, and secured in such aligned superposition. With a three-sided outermost or end loop, four open loops or U- bends must be provided; with a five-sided outermost or end loop, six open loops or U-bends must be provided. In every case, there'must be one loop more than the number of sides desired, and in each instance, .the endmost thereof overlaps the first thereof and is secured thereto to close the outermost 'or end convolution of the spring.

In Fig. l, I show the endmost U-bend 22' spring spaced apart, or sprung apart, from the first U- bend 22"; in Fig. 2, I show U-bend 22' in place on top of and over loop 22" and aligned therewith, and locked in suchoverlapping and abutting position by means of ear or lug 28 extend ing from the outer side wall of loop. 22;

It is by means of this overlapping of the U- bends and the securing and locking of same in such overlapping position that I close the outermost or end loop, and in this manner attain the perfection desired in the shape of said loop, and in the constancy of its size. I am familiar with spiral springs of the cylindrical or'helical type in which the outermost or end convolutions are closed, but with none of theexpedients heretofore adopted are the advantages I secure attainable. I

When forces are applied to spring l (Fig. 2) along a line parallel to its axis, coil I8 is first eifected, and transmits the pressure directly to coils' [6; upon release of the pressure the coils will expand and the spring will resume its normal position. In a spring with an open end convolution, this normal operation does not take place except when the pressure applied to the spring is centralized thereover and applied exactly in the axial plane. For example, if loop I8 were open, as in the position of Fig. 1,'and pressure were applied thereto at U-bend 22 along y a line parallel to the axis of the spring, the result would be a distortion of loop l8 and a. delayed transmission of the pressure to the coils, since the open end convolution would yield to the pressure to an extent to which a closed end loop could not yield.

When angular forces are applied to spring In, and are directed to loop 8, a double spring effect is obtained which relieves coils 16 of the strains which otherwise would be imposed thereupon with disastrous results. The inner coils are not adapted to absorb angularly directed forces, and if subjected thereto quickly become distorted and useless.

Thus, if angular pressure is applied to spring I0, as in Fig. 1, with the outermost convolution open, the distortion of said convolution would be directly transmitted to the inner coils and twist them out of their true circular shape. In Fig. 2, the outermost or end loop is closed, in accordance with my invention, and when pressure, as P, is applied thereto along the line of the arrows, the shape of loop l8 changes from square to diamond; loop [8 flexing at the midpoints of troughs 24 of the U-bends or open loops on each side of bend 22 and then, simultaneously and concurrently therewith, at points 30 where sides 26 of said U-bendson each side of bend 22 merge with and blend into loop sides 20.

This double spring efiect relieves coils [6 of theVbur-den, or at least of part thereof, of absorbing these angularly applied forces P. If loop I8 were open, as in Fig. 1, the U-bends would not accomplish this double yielding action, and said loop I8 would merely be twisted somewhat out of shape. The combination of closed loop [8 with U-bends' or open loops at the corners is essential to the desired operation of said outermost or end loop, and insures its return to normal size and shape upon release or relaxation of the angularly applied pressure.

In Fig. 2, I illustrate the manner in which a number of springs are assembled. Links 32 are provided with hooks 34 at the ends thereof. These hooks 34 fit over and completely close around trough portions 34 of the U-bends of adjacent springs ID. The links may be of any desired length; shorter or longer as more or less springunits are desired to be incorporated into any given spring assembly. The U-shape of the open loops or bends, and the sides thereof, will effectively prevent the links from slipping, and the consequent displacement of the spring units relative to each other. I

Having now described my invention, what I claim and desire to secure by Letters Patent is:

1. In a device of the character described, a. closed outermost or end convolution comprising a length of wire in which is formed a number of .U-bends, the endmost of which is disposed coincidentally on top of and in overlying relation to the first U-bend, and means integral with said endmost bend extending underneath the first U- bend for securing said endmost bend to the first thereof in the above-described relation.

- 2. In a device of the character described, a length of wire or similar material formed into a closed loop or coil, of substantially plane polygonal shape, having substantially straight sides to the number 1:, and U-bends constituting the angles or meeting points of the sides, and a U- bend at the beginning and a U-bend at the end of said length of wire, all of said U-bends totalling the number :n plus one, the endmost or last of which U-bends is disposed coincidentally with and on top of the first of said U-bends, and means comprising 2. lug extending from the tip end of said last or endmost U-bend disposed to pass underneath said first U-bend and secure same to the last U-bend in the above-described relation.

LOUIS KllVlBRIG. 

